Advice on setting up my own HR Consultancy

Does anyone have advice on setting up as a sole trader, do’s don’ts and how to set your prices? There seems so much to consider! Has anyone ideas on how to determine a scope of service as a generalist HR professional, how much would you include and what would you have as extra add ons? I think I may have two clients already asking for a regular HR service on a 12 month contract basis and so I’m racing to get everything set up! Thanks in advance.